End-functionalized polymers by controlled free-radical polymerization process and polymers made therefrom

ABSTRACT

A controlled free-radical polymerization process for forming end-functionalized polymers is disclosed, particularly by degenerative iodine transfer. The end-functionalized polymers are characterized by a polydispersity less than 2.5 and a predetermined molecular weight. The end-functionalized polymers are useful as reactive intermediates in condensation polymerization, chain polymerization and heterogeneous polymerization reactions.

This is a division of patent application Ser. No. 08/956,571 filed Oct.23, 1997, now U.S. Pat. No. 6,143,848.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to end-functionalized polymers, processes for,making the same, and polymers made using such end-functionalizedpolymers.

More particularly, the invention relates to a controlled free-radicalpolymerization process for forming end-functionalized polymers,particularly by a degenerative iodine transfer (DIT) and atom transferradical polymerization (ATRP) processes.

The resultant end-functionalized polymers have a high degree offunctionality, a polydispersity less than 2.5, and a predeterminedmolecular weight. The resultant end-functionalized polymers are usefulas reactive intermediates in condensation polymerization, chainpolymerization and heterogeneous polymerization reactions.

2. Description of the Prior Art

Controlled free-radical polymerization processes, including ATRP andDIT, are prior art processes for free-radical polymerization. Indegenerative iodine transfer polymerization, chain growth is controlledby iodine atoms, which reversibly react with the growing polymer chainends thereby, limiting side reactions. Iodine atoms are introduced intothe reaction using iodine transfer reagents, and polymer radicals areinitially generated with a small amount of a conventional initiator.

The atom transfer radical polymerization process can also produceproducts with more uniform and more highly controlled architecture. Theprocess includes free-radical polymerization of one or more monomers, inthe presence of an initiator having a transferable atom or group, and atransition metal compound with an appropriate ligand. The transitionmetal compound has the formula ML_(n), the ligand L being any N-, O-,P-, or S-containing compound, which can coordinate to the transitionmetal through a σ-bond or any carbon-containing compound which cancoordinate through a π-bond, such that direct bonds between thetransition metal in growing polymer radicals are not formed. The formedcopolymer is then isolated.

Application of the degenerative transfer process in the production ofpolymers is disclosed in the following references: Japanese Kokai No.4-132706 (1992), assigned to Nippon Shokubai, discloses a DIT processfor the production of telechelic polymers having hydroxyl groups at theends. The initial formula of the reagent used is X—R—X′ wherein X isbromine or iodine and R is a bivalent C1-C8 hydrocarbon. The reagentsused in the method are not efficient, and thus require a great excess ofthe iodo reagents (0.01-10 moles monomer per mol of the reagent) toproduce polymers having a molecular weight of 1500 and greater. Further,the molar ratio of halide reagent to conventional initiator is extremelyhigh, being on the order of 50 to 500 to 1. The functionalizationprocess for converting the chain-end iodides to a hydroxyl group is alsoinefficient. In this regard, four reactions are specified: (1)hydrolysis; (2) substitution with diols; (3) substitution with hydroxyamines; and (4) substitution with carboxylates. Reactions 1 and 2promote side reaction with ester containing polymers whereas reactions 3and 4 are often slow and incomplete. The molecular weights obtained bythe method disclosed in Nippon Shokubai Japanese Kokai No. 4-132706 arefor the most part high, that is, in excess of 5000.

U.S. Pat. No. 5,439,980 issued in 1995 to Daikin Industries discloses aDIT process wherein block copolymers are synthesized using an iodinereagent and two monomers, which are added simultaneously. The processrelies on large reactivity differences between the monomers, andintroduces no functional endgroups.

U.S. Pat. No. 5,455,319 issued in 1995 to Geon describes the use of DITto produce vinyl chloride homopolymers and some random copolymers ofvinyl chloride. The iodine transfer reagents employed in the '319 Patentare efficient in that they are activated reagents. But the DITpolymerization process in an aqueous media is described only for vinylchloride polymers and the patent does not address end-functionalpolymers.

K. Matyjaszewsky, in Macromolecules, Vol. 28, pages 2093-2095 and8051-8056 (1995) describes a process for controlled polymerization usingiodine compounds. Neither efficient difunctional transfer agents norreagents having an incorporated functional group are disclosed.

Atom transfer radical polymerization (ATRP), on the other hand, is alsodescribed in the prior art. For example, WO 96/304212 to Matyjaszewskiand Carnegie-Mellon University describes metal catalyzed free-radicalpolymerization using an alkyl halide initiator to control thepolymerization.

The general idea of using a functionalized initiator for ATRP orfunctionalizing the halide end group from an ATRP polymer is mentionedin J-S Wang, D. Grezsta, K. Matyjaszewski, Polym. Mater. Sci. Eng., 73,416 (1995). No examples are provided in the article, nor is it obvioushow to carry out the hypothesis.

The synthesis of a polymer with an allyl end group using an allylinitiator or substitution with allyl trimethylsilane, and the synthesisof polystyrene with one amine end group using a trimethylsilyl azidereaction followed by hydrolysis are described in Y. Nakagawa, S. Gaynor,K. Matyjaszewaski, Polym. Prep., Am. Chem. Soc., Polym. Div., 37(1), 577(1996).

A polymer with a vinyl acetate group formed using a functionalizedinitiator is described in K. L. Beers, S. G. Gaynor, K. Matyjaszewski,Polym. Prep., Am. Chem. Soc., Polym. Div., 37(1), 571 (1996).

Hydroxy end-functionalized polymers, and processes for making the sameusing non-living free-radical polymerizations, are also disclosed inprior art, European Patent No. EP 06223 78A 1 to Goldschmidt AG. Thispatent describes polymethacrylate diols and a process for making thesame. The process is a conventional free-radical polymerization processinitiated in the presence of a large amount of mercaptoethanol chaintransfer agent. The polymer chain starts from mercaptoethanol andterminates with the methacrylate group, which is then converted to ahydroxyl containing moiety by a selective substitution reaction using analiphatic diol in the presence of Ti(OR)₄. The chain end substitutionreaction specified is a moisture-sensitive and costly process.Furthermore, the reaction is only selective and efficient for methylmethacrylate polymers thus limiting the general applicability.

U.S. Pat. No. 5,391,655 issued in 1995 to Nippon Shokubai describes aprocess wherein vinyl monomers are polymerized by conventionalfree-radical polymerization in the presence of a great excess of adisulfide reagent containing two hydroxyl groups at each end. Theformula of the disulfide reagent is HO—R—S—S—R′—OH and the molarconcentration of disulfide reagent is greater than 50 times that of theinitiator and at least 0.5 of the vinyl monomer. The process is flawedin that it cannot produce pure difunctional telechelics and in thatlarge amounts of the functionalization reagents are needed.

Thus, there exists a need for a process capable of providing anend-functionalized polymers having a predictable molecular weight, highdegree of functionality, and low polydispersity. The process must besufficiently flexible to control molecular weight as well as polymerarchitecture. A living or controlled free-radical process followed by anefficient functionalization step provides a solution and is presentedherein. Efficient iodine transfer agents or bromide initiators andinexpensive functionalization reagents are also needed.

The resultant end-functionalized polymers are useful as reactiveintermediates for condensation polymerization of polyurethanes,polyesters and epoxides; chain polymerization to form graft copolymersand crosslinked copolymers; and polymeric emulsifiers.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a process for controlled free-radicalpolymerization followed by chain-end conversion for makingend-functionalized polymers. Such polymers are also generally referredto as telechelic polymers. They are also known as macromonomers in thespecific case where the end groups are unsaturated and polymerizable.Degenerative iodine transfer and atom transfer radical polymerizationare particular examples of controlled free-radical polymerization. Thepolymers produced by these methods have a predictable molecular weight,halogen end-groups, and low polydispersity. The process disclosed hereinincludes both efficient transfer agents as well as efficient andminexpensive reagents. The process also describes the conversion ofhalogen end-groups to desired functional groups, using efficientreagents. The resultant end-functionalized polymers are useful asreactive intermediates in condensation polymerization, chainpolymerization and heterogeneous polymerization reactions.

In the first aspect of this invention, a process for forming a polymerhaving at least one functionalized end group is disclosed. The processinvolves heating a mixture of an iodine reagent having at least oneiodine end group, a free-radical initiator, and at least onepolymerizable monomer. The molar ratio of the free-radical initiator tothe reagent is about 10 to 0.001. The molar ratio of the polymerizablemonomer to the reagent is about 10 to 1,000. The iodine end group isconverted to the functionalized end group by reaction with anucleophilic reagent.

According to a second aspect of the invention, a mono-end-functionalpolymer is disclosed, which has the formula:

R-polymer-Y—R₂—Z₁  (I)

where R contains at least one radical stabilizing group and has at least1-50 carbon atoms, the polymer and the radical stabilizing group areattached to the same carbon atom in R, and the radical stabilizing groupis selected from the group consisting of an aryl, alkene, ester, acid,amide, ketone, nitrile, halogen, isocyanate, nitro and amine.

where R₂ is a substituted or unsubstituted alkylidene group having 1-20carbon atoms or is not present when Z₁ is directly bonded to thepolymer,

where Y is selected from the group consisting of oxygen, sulfur, andN(R₅), where R₅ is hydrogen or a substituted or unsubstituted alkylgroup or is not present when Z₁ is directly bonded to the polymer, and

where Z₁ is selected from the group consisting of: OR₁, N(R₁)₂, SR₁,COOR₁, COOM, olefin of the type —CR₁═C(R₁)₂, epoxide of the type

SO₃M, PO(OR₁)₂, PO(R₁)3, P(R₁)₃, —N═C═O and —CR₁═O, wherein R₁ is equalto H or a group having 1-20 carbon atoms, R₁ being the same or differentfor any Z₁ having more than one R₁, and wherein M is a metal ion.

The term “polymer” is used to define a molecular chain containing 5 to500 monomer units, including mono- or disubstituted vinylic units, suchas —[—CH(R₆)—C(R₄)(X)—]— where R₄ is selected from hydrogen, methyl,hydroxymethyl, phenyl, halogen, or CH₂COOH, X is selected from the groupconsisting of an alkyl, aryl, nitrile, halide, alcohol, carboxyl,sulfonyl, ester of the type —CO—O—R₃, acetate of the type —O—CO—R₃,ether of the type —O—R₃, carboxyamide of the type —CO—N(R₃)₂ and amineof the type N(R₃)₂, wherein R₃ is equal to H or a group having 1-30carbon atoms, R₃ being the same or different for any X having more thanone R₃, where R₆ is selected from hydrogen, methyl, phenyl, halogen, orCH₂COOH, alkyl, aryl, nitrile, halide, alcohol, carboxyl, sulfonyl,ester of the type —CO—O—R₃, acetate of the type —O—CO—R₃, ether of thetype —O—R₃, carboxyamide of the type —CO—N(R₃)₂ and amine of the typeN(R₃)₂, or diene monomer units. The polymer chain may be composed of aseries of one monomer or a random mixture of two or more of thesemonomers. In addition, the chain may have a non-random distribution ofthe monomers, such as when the distributions are a diblock, triblock,multi-block, or graft structures. The polymer is formed in the DIT orATRP process and is preferably poly (n-butyl acrylate), polystyrene,poly(ethyl acrylate), poly(ethylhexyl acrylate), orpoly(acrylonitrile-co-n-butyl acrylate).

According to a third aspect of the invention, a bis-end-functionalpolymer is disclosed, which has the formula:

Z₂—R-polymer-Y—R₂—Z₁  (II)

where R, Y, R₂, and Z₁ are as previously noted, Z₂ is selected from thesame group as Z₁, and Z₁ and Z₂ are independently selected.

According to a fourth aspect of the invention, a bis end-functionalpolymer is disclosed, which has the formula:

Z₁—R₂—Y-polymer-R-polymer-Y—R₂—Z₁  (III)

where R, Y, R₂, and Z₂ are selected as previously noted.

According to the fifth aspect of the invention, ATRP can be used to forma prepolymer with bromide or chloride end groups, which can befunctionalized by conversion of end group by reaction with anucleophilic reagent.

One advantage of the present invention is that the degenerative iodinetransfer process disclosed employs efficient chain transfer agents.

Another advantage of the present invention is that the degenerativeiodine transfer process disclosed provides both molecular weight andpolymer architecture control.

Still another advantage of the present invention is that a degenerativeiodine transfer process is disclosed wherein inexpensive iodinereagents, in amounts much less than those specified in the prior art,are disclosed.

Another advantage of the present invention is that a degenerative iodinetransfer process disclosed is effective with a wide variety ofmonomers—that is, more than fluorinated monomers, can be used in thepractice of the DIT process.

Still another advantage of the process disclosed is the efficientend-group conversion applied to polymers prepared by ATRP.

Another advantage is that the resulting end-functionalized polymers, ortelechelic polymers, can be used in a condensation, radical, anionic, orgraft polymerization processes.

Still another advantage is that using the described process a widevariety of monomers can be used.

Another advantage is that a wide variety of functional end groups can beintroduced with the appropriate choice of nucleophilic reagents.

Still another advantage is that the iodine can be recycled in thedescribed process.

Another advantage is that the efficient iodine transfer reagents cancontain one functional group and only one iodine which lowers the amountof iodine used in the process compared to bis iodine reagents.

Still another advantage is that polyacrylate diol polymers can be madewhich improve properties and give higher hydrolytic and UV stabilitywhen incorporated in polyurethanes, polyesters, polyamides,polycarbonates, and polyepoxides.

Another advantage is that olefinic end-functional polymers, also knownas macromonomers, can be produced which can be used to prepare graftcopolymers in chain polymerization to form block and graft copolymers.

Still another advantage is that polymers can be formed with ionic endgroups, useful as polymeric surfactants.

Another advantage is that polymers can be formed with two differentfunctional end groups.

Still another advantage is that end-functional diblock or triblockcopolymers can be made.

Still other benefits and advantages of the invention will becomeapparent to those skilled in the art upon reading and understanding ofthe following detailed specification.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic view of the DIT process and functionalizationutilized in practicing the subject invention;

FIG. 2 is a schematic view illustrating the synthesis of polymer diolsby the DIT process utilized in practicing the subject invention;

FIG. 3 illustrates examples of Type I mono-functional polymers of thesubject invention;

FIG. 4 illustrates examples of Type I difunctional polymers of thesubject invention;

FIG. 5 illustrates examples of Type II functionalized polymers of thesubject invention;

FIG. 6 is a schematic view of the ATRP process and functionalizationutilized in practicing the subject invention;

FIG. 7 illustrates the MALDI mass spectrum of the PIE prepolymer formedin Example 5;

FIG. 8 illustrates the MALDI mass spectrum of the end-functionalized PIEpolymer formed in Example 18; and

FIG. 9 illustrates the MALDI mass spectrum of the end-functionalized DIXpolymer formed in Example 17.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to end-functionalized polymers by acontrolled free-radical polymerization process, followed by chain-endconversion. More particularly, the invention relates to the formation ofmonofunctional and difunctional polymers, including telechelic polymers,and macromonomers. The controlled free-radical polymerization processesare degenerative iodine transfer (DIT) and atom transfer radicalpolymerization (ATRP).

The DIT process of the present invention is used to form prepolymerswith one or more iodine end groups. These iodine end groups areconverted in a second step to the desired functional groups. The processis illustrated generally in FIG. 1 and involves heating a mixture of anactivated iodine reagent having at least one iodine end group, afree-radical initiator, and at least one polymerizable monomer. Theprocess is illustrated for the production of one specific class ofpolymer diols in FIG. 2.

The iodine reagents of the subject DIT process all contain one or moreradical stabilizing groups, attached to the carbon(s) adjacent to theiodine atoms. This group activates the reagents towards iodine transferand makes the reagents efficient.

The iodine reagents to be distinguished in particular are: (1)mono-iodine reagents without a functional group, R—I; (2) mono-iodinereagents with a functional group, Z₂—R—I; and (3) di-iodine reagents,I—R—I.

Reagents of the type R—I can be used to make monofunctional polymers,reagents of the type Z—R—I and I—R—I can be used to make difunctionalpolymers with functional groups at both ends of the polymer. Thedistinction between Z₂—R—I and I—R—I is that the former reagent can beused to make difunctional polymers with two different end groups, whilethe latter reagent can only lead to di-functional polymers with twoidentical end groups.

The mono-iodine reagents without a functional group are of the formula:

R—I  (IV)

where R contains at least one radical stabilizing group and has 1-50carbon atoms, the polymer and the radical stabilizing group are attachedto the same carbon atom in R, and the radical stabilizing group can bean aryl, alkene, ester, acid, amide, ketone, nitrile, halogen,isocyanate, nitro and amine.

Examples of the radical stabilizating group include C₆H₄Me, OC(═O)-Me,F, and CN. Preferred R—I reagents are depicted below:

The mono-iodine reagents with a functional group are of the formula:

Z₂—R—I  (V)

where R, as noted above, contains at least one radical stabilizing groupand has 1-50 carbon atoms, the polymer and the radical stabilizing groupare attached to the same carbon atom in R, and the radical stabilizinggroup is selected from the group consisting of an aryl, alkene, ester,acid, amide, ketone, nitrile, halogen, isocyanate, nitro and amine, and

where Z₂ is selected from the group consisting of: OR₁, N(R₁)₂, SR₁,COOR₁, COOM, olefin of the type —CR₁═C(R₁)₂, epoxide of the type

SO₃M, PO(OR₁)₂, PO(R₁)₃, P(R₁)₃, —N═C═O and —CR₁═O, wherein R₁ is equalto H or a group having 1-20 carbon atoms, R₁ being the same or differentfor any Z₂ having more than one R₁, and wherein M is a metal ion.Preferred reagents of the type Z₂—R—I are depicted below:

The di-iodine reagents without a functional group are of the formula:

I—R—I  (VI)

where R, as previously noted, contains at least one radical stabilizinggroup and has 1-50 carbon atoms, the polymer and the radical stabilizinggroup are attached to the same carbon atom in R, and the radicalstabilizing group is selected from the group consisting of an aryl,alkene, ester, acid, amide, ketone, nitrile, halogen, isocyanate, nitroand amine.

Preferred reagents of the type I—R—I are depicted below:

The iodine reagent selected for the polymerization is dependent on thetype of monomer and the architecture desired. A balance between the rateof transfer and rate of reinitiation needs to be maintained. Forexample, 1-iodo-1-phenylethanol is a suitable reagent for thepolymerization of styrene and n-butyl acrylate. But it does not workproperly for the polymerization of vinylacetate or vinylidene chloridebecause the radical formed after transfer is not reactive enough forreinitiation. To the contrary, methylene iodide does not transferquickly enough to provide controlled (polymerization occurs-butuncontrolled) polymerization of styrene or n-butyl acrylate: For thepolymerization of vinyl acetate, perfluorohexyliodide is used instead of1-iodo-1-phenylethanol.

The suitable free-radical initiators useful in the practice of thepresent invention include any conventional free-radical initiators knownin the art. These initiators can include hydroperoxides, peresters,percarbonates, peroxides, persulfates and azo initiators. Specificexamples of some initiators include hydrogen peroxide, tertiary-amylperoxide, dibenzoyl peroxide (BPO), potassium persulfate, andmethylethyl pentyl peroxide.

In the preferred embodiment, the free-radical initiators areazo-initiators such as azobisisobutyronitrile (AIBN), azobiscyanovalericacid (ADVA), azobis(hydroxyethylcyanovaleramide) (VA-080),azobis(cyclohexanecarbonitrile), 2.2′azobis(4-methoxy-2,4-dimethylvaleronitrile),2.2′-azobis[2-methyl-N-(2-hydroxyethyl)propionamide]. Preferably, themolar ratio of the free-radical initiator to the reagent is 10 to 0.001,with 2 to 0.01 being preferred. The described initiators may optionallycontain the same functional group as Z₁ to increase the functionality ofthe final polymer.

Suitable monomers for use in the present invention include: C₃-C₆monoethylenically unsaturated carboxylic acids, and the alkaline metaland ammonium salts thereof. The C₃-C₆ monoethylenically unsaturatedcarboxylic acids include acrylic acid, methacrylic acid, crotonic acid,vinyl acetic acid, maleic acid, flunaric acid, and itaconic acid.Acrylic acid and methacrylic acid are the preferred monoethylenicallyunsaturated carboxylic acid monomers.

The acid monomers useful in this invention may be in their acid forms orin the form of the alkaline metal or ammonium salts of the acid.Suitable bases useful for neutralizing the monomer acids includes sodiumhydroxide, ammonium hydroxide, potassium hydroxide, and the like. Theacid monomers may be neutralized to a level of from 0 to 50% andpreferably from 0 to about 20%.

Monoethylenically unsaturated monomers containing no carboxylic acidgroups are also suitable in the present invention. Typical examplesinclude alkyl esters of acrylic or methacrylic acids such as methylacrylate, ethyl acrylate, butyl acrylate; hydroxyalkyl esters of acrylicor methacrylic acid such as hydroxyethyl acrylate, hydroxypropylacrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate;acrylamide, methacrylamide, N-tertiary butylacrylamide,N-methylacrylamide, N,N-dimethyl acrylamide; acrylonitrile,methacrylonitrile, dimethylaminoethyl acrylate, dimethylaminoethylmethacrylate, phosphoethyl methacrylate, N-vinyl pyrrolidone,N-vinylformamide, N-vinylimidazole, vinyl acetate, styrene, maleimide,hydroxylated styrene, styrenesulfonic acid and salts thereof,vinylsulfonic acid and salts thereof, and2-acrylamido-2-methylpropanesulfonic acid and salts thereof. Othermonomers include halogenated vinylic monomers such as vinyl chloride,vinylidene chloride, and vinylidene fluoride.

Other suitable monomers include acrylamides, alkyl and aryl amidederivatives thereof, and quaternized alkyl and aryl acrylamidederivatives and dienes such as butadiene and isoprene.

The molar ratio of the polymerizable monomer to the iodine reagent isabout 10 to 1,000, with 15 to 50 being preferred. In the preferredembodiment, the polymerizable monomers are n-alkyl acrylates, acrylicacid, styrene, and acrylonitrile.

The monomers can be added pure or as combinations of monomers to formcopolymers. Because of the living polymerization character, differentmonomers can also be added sequentially, eventually leading tofunctionalized block copolymers.

These monomers will result in a polymer having a “polymer” backbonecomprising 5 to 500 monomers units, including vinylic monomer units ordisubstituted vinylic units, such as —[—CH(R₆)—C(R₁)(x)-]— where R₄ isselected from hydrogen, methyl, phenyl, halogen, or CH₂COOH, X isselected from the group consisting of an alkyl, aryl, nitrile, halide,alcohol, carboxyl, sulfonyl, ester of the type —CO—O—R₃, acetate of thetype —O—CO—R₃, ether of the type —O—R₃, carboxyamide of the type—CO—N(R₃)₂ and amine of the type N(R₃)₂, wherein R₃ is equal to H or agroup having at least 1-30 carbon atoms, R₃ being the same or differentfor any X having more than one R₃, where R₆ is selected from hydrogen,methyl, phenyl, halogen, or CH₂COOH, alkyl, aryl, nitrile, halide,alcohol, carboxyl, sulfonyl, ester of the type —CO—O—R₃, acetate of thetype —O—CO—R₃, ether of the type —O—R₃, carboxyamide of the type—CO—N(R₃)₂ and amine of the type N(R₃)₂, or diene monomer units. Thepolymer chain may be composed of one monomer or a random mixture of twoor more of these monomers. In addition, the chain may have a non-randomdistribution of the monomers, such as when the distributions are adiblock, triblock, multi-block, or graft structure. The polymer isformed in the DIT or ATRP process. The “polymer” is preferably a poly(n-butyl acrylate), polystyrene, poly(ethyl acrylate), poly(ethylhexylacrylate), or poly(acrylonitrile-co-n-butyl acrylate).

The polymerization step is preferably conducted in the presence of asolvent or co-solvent. Examples of solvent or co-solvents useful in thepresent invention include compatible hydrocarbons, aliphatic alcohols,glycols, ethers, glycol ethers, pyrrolidones, N-alkyl pyrrolidones,polyethylene glycols, polypropylene glycols, amides, carboxylic acidsand salts thereof, esters, carbonates, organosulfides, sulfoxides,sulfones, alcohol derivatives, hydroxyether derivatives such asCARBITOL® or CELLOSOLVE®, amino alcohols, ketones, and the like,derivatives thereof, and mixtures thereof. Specific examples includeethylene glycol, propylene glycol, diethylene glycol, glycerine,dipropylene glycol, tetrahydrofuran, and the like, and mixtures thereofin a 50% by weight solution. The most suitable solvents include toluene,amyl acetate, butyl acetate, pseudocumene, dimethylformamide andtetrahydrofuran. The most preferred solvent for the polymerization stepis toluene. However, the polymerization step can be conducted in bulk.

The polymerization step is carried out at 0-150° C., preferably at from40-80° C.

The resultant prepolymer is functionalized by reaction with anucleophilic reagent and a weak base. Suitable nucleophilic reagents forpractice in the present invention include thiols, amines, alcohols,sulfites, and phosphines. The nucleophilic reagent has the generalformula:

Z₁—R₂—YH  (VII)

where Y, Z₁, and R₂ are selected as previously noted.

The preferred reagents are:

The nucleophilic reagents are preferably used in a 1:1 ratio withrespect to iodine end groups. In the preferred embodiment, suitablenucleophilic reagents include meccaptoethanol, mercaptopropanol, allylmercaptan, thioacetic acid, mercaptopropionic acid.

Suitable bases for use in the functionalization step include ZnO,pyridine, 4-dimethylaminopyridine (DMAP), diazabicyclo[5,4,0]undec-7-ene(DBU), K₂CO₃, K₃PO₄, NaHCO₃, basic alumina, Et₃N, CaO, and1,4-diazabicyclo[2,2,2]octane (DABCO). In the preferred embodiment, thebase used is K₂CO₃.

The functionalization step can also be conducted in the presence of asolvent or co-solvent. Examples of solvents or co-solvents useful in thepresent invention include compatible alkanes, arenes, aliphaticalcohols, glycols, ethers, glycol ethers, pyrrolidones. N-alkylpyrrolidones, polyethylene glycols, polypropylene glycols, amides,carboxylic acids and salts thereof, esters, carbonates, organosulfides,sulfoxides, sulfones, alcohol derivatives, hydroxyether derivatives suchas CARBITOL® or CELLOSOLVE®, amino alcohols, ketones, and the like.derivatives thereof, and mixtures thereof. Specific examples includeethylene glycol, propylene glycol, diethylene glycol, glycerine,tetrahydrofuran, and the like, and mixtures thereof. The most suitablesolvents include toluene, amyl acetate, butyl acetate, pseudocumene,N,N-dimethylformamide (DMF) and tetrahydrofuran (THF). The preferredsolvent for the functionalized step is DMF.

The functionalization step can be carried out at a temperature range of−50° C. to 100° C. In the preferred embodiment, the temperature range ofthe functionalization step is from −10° C. to 70° C.

In the preferred embodiment, iodine-containing salts generated as aby-product of the functionalization step are recycled for use in thetransfer reagent synthesis. The addition of base does not onlyfacilitate substitution, it also serves to neutralize any hydriodic acidthat is formed. The resulting iodide salts can be separated from thepolymer/solvent mixture using conventional methods. The hydriodic acidcan be recovered from the iodide salts or those salts can be useddirectly in the synthesis of the iodine reagents. This process resultsin an additional significant cost reduction of the overallfunctionalization process.

Preferably, prepolymers made by the DIT process disclosed herein arefunctionalized using the functionalization process disclosed herein. Wehave discovered that our functionalization process is advantageous inthat the reagents are mild and minimize side reactions with the polymerbackbone or end groups. Furthermore, the reagents are cost efficient andlead to very high degrees of functionalities. Yet, another advantage isthat the functionalization process can be carried out such that iodinecan be recycled.

The resultant end-functionalized polymers formed by the disclosed DITprocess and functionalized in accordance with the process disclosedherein are of three types: Type I where only one end of the chaincontains a reactive functional group; Type II where both ends of thepolymer chain contain reactive functional groups, which can be the sameor different, and Type III where both ends of the polymer chain carryidentical functional groups. In either event, the polymer between theend groups can be random, di-, tri- or multiblock, graft or star shaped,or gradient copolymers. The end-functionalized polymers have apolydispersity less than 2.5.

The Type I end-functionalized polymers may contain reactivefunctionalities such as a hydroxyl, amine, carboxyl, epoxy, isocyanate,and the like. The molecular weight of these polymers can range anywherefrom 500 to 20,000 Daltons. They are preferably used to introduce graftsinto polymers that contain a reactive pendant group on their backbone.The low-molecular weight versions of the Type I polymers are also usefulas a polymeric emulsifiers and co-surfactants.

The reactive functionality in the Type I polymers could also be apolymerizable vinyl group where X in the previously described formula isan acrylic, methacrylic, vinyl benzene, vinyl ester, etc. In this case,the end-functionalized polymer is a macromonomer. These macromonomersare useful in polymerization with a variety of monomers to createside-chain block or graft copolymers.

The Type I end-functionalized polymers can be of the formula:

R-polymer-Y—R₂—Z₁  (I)

where R, Y, R₂, Z₁, and “polymer” are selected as previously noted.

The Type II end-functionalized polymers are of the formula:

Z₂—R-polymer-Y—R₂—Z₁  (II)

where R, Y, R₂, Z₁, Z₂, and “polymer” are selected as previously noted.

The Type III end-functionalized polymers are of the formula:

Z₁—R₂-Y-polymer-R-polymer-Y—R₂—Z₁ (III)

where R, Y, R₂, Z₁, and “polymer” are selected as previously noted.

Specific examples of the Type I end-functionalized polymers of theinstant invention are illustrated in FIG. 3. FIG. 4 illustrates thedifunctional Type II polymers. FIG. 5, on the other hand, isillustrative of the Type III difunctional polymers.

End functionalization in accordance with the present invention can alsobe used for polymers produced by an atom transfer radical polymerization(ATRP) process as illustrated in FIG. 6. The ATRP process is disclosedin WO 96/30421 and is incorporated herein by reference. ATRP polymersdiffer from DIT polymers in that bromide or chloride terminatedprepolymers are formed in ATRP, versus the iodide terminated prepolymersin DIT polymerization. The preferred nucleophilic reagents that can beused to efficiently functionalized prepolymer made by ATRP are sulfurreagents of the formula:

Z₁—R₂—SH  (VIII)

where R, Y, R₂, and Z₁ are selected as previously noted.

These reagents give selective substitution with polyacrylates havingbromide end groups without interchanging on the ester groups in thebackbone of the polymer. The latter side reaction is the dominant one ifany other reagent is used to introduce the claimed end groups on anacrylate polymer. Examples of the reagents are:

The uses for the end-functionalized, telechelic polymers of the presentinvention include the use of the mono-functional polymer (Type I)containing reactive functionalities, such as hydroxyl, amine, carboxyl,epoxy, isocyanate, or the like, as grafting reagents for reacting withpolymers containing a reactive pendant group on their backbone.Molecular weights of the end-functionalized polymers could range between500 to 20,000. The low-molecular weight versions of these polymers couldalso be useful as polymeric emulsifiers and as co-surfactants. The TypeI polymers, having, for example, a polymerizable vinyl end group, couldbe used in copolymerization with a variety of monomers to createside-chain block or graft copolymers.

The Type II and Type III difunctional polymers have two reactive endgroups such as a hydroxyl, amine, carboxyl, epoxy, isocyanate, etc. Theend groups can be different (Type II) or the same (Type III). As such,they have various applications in the polymer industry, including thefollowing:

As chain-extenders in the manufacture of polyesters, polyurethanes,polyamides, polycarbonates, and epoxy resins.

As liquid reactive polymers useful as crosslinkers and impact modifiersin polyesters and epoxy resins.

In the manufacture of water-borne polyurethanes and alkyd resins.

As tackifier, adhesion promoters and compatibilizers in polymericblends.

In the synthesis of thermoplastic elastomers, block copolymers, andpolymer network.

As low melt-flow, reactive polymers, useful for crosslinkable powdercoating compounds.

Other industrial applications for difunctional polymers having hydroxylgroups at both terminals are described in U.S. Pat. No. 5,391,665, whichis incorporated herein by reference.

The Type II and III polymers having polymerizable groups, e.g., vinylgroups, at both ends could be used to manufacture cross-linked polymericemulsions and dry resin products, or in UV-cure, solvent-based coatings,powder coatings, and high-temperature cure adhesive/binder materials.

The end-functionalized or telechelic polymers of the present invention,especially when they are macromonomers, can be employed in further,conventional polymerization processes, including condensationpolymerization, radical polymerization, anionic polymerization, andgraft polymerization, to make polyurethanes, polyesters, polyamides,polycarbonates, and polyepoxides having improved properties. Theseproperties are derived from the fact that the process of the presentinvention allows for control of the molecular weight of the polymer,targeting a molecular weight of the polymer, producing block polymers,and using a wide variety of monomers to make improved polymers. As isseen in Example 23, a polyurethane made using end-functionalizedacrylated polymer of the present invention has improved hydrolyticstability (as shown in Table II). Further, the polyurethane polymer willprovide improved ultraviolet light stability due to the fact that thepolymer can be made using an end-functionalized polyacrylate.

TABLE II Diol Component of Polyurethane Media of Poly Poly Poly ExposurePolyester Polyether (THF) MMA (nBA) % MW 100 100 100 100 100 (Control) %MW after 49 94 92 67 92 exposure to Water % MW after <1 59 45 21 83exposure to 10% KOH

The present invention will now be described in greater detail in thefollowing non-limiting examples. In these examples, the abbreviation PIEstands for 1-iodo-1-phenylethanol and DIX stands for α,α′-diiodoxylene.MALDI Analyses are matrix assisted laser desorption—time of flight massspectroscopic analyses using indole acrylic acid as the matrix.

EXAMPLE 1 Synthesis of 2-iodo-2-phenylethanol (PIE) in an AqueousSolvent

2-iodo-2-phenylethanol was synthesized as described in Golumbic, C. andCottle, D. L. J. Am. Chem. Soc. 61, 996 (1939). An aqueous HI solution(81.7 grams, 54.7%) and 556 ml of water were added to a 1 L reactionflask equipped with an addition funnel, which was cooled to zero degreesC. Styrene oxide (40 grams) and 50 grams of ethanol were added to theaddition funnel. The styrene oxide solution was added dropwise to theflask over a 40-minute period during which a white precipitate wasformed. Filtration over a fritted glass funnel followed by drying undervacuum for four hours yielded 69.8 grams of a white solid having amelting point of 62-66° C. The solid was dissolved in 560 ml of ethanoland poured into rapidly stirred water (2.5 L containing 100 ml of 5%NaHSO₃). The white precipitate was collected on a fritted glass funneland dried in a vacuum oven at room temperature for four hours in thepresence of P₂O₅ as a desiccant. The white solid (24 grams) had amelting point of 75.5-76° C. NMR analysis was consistent with thereports in the above-cited literature.

EXAMPLE 2 Synthesis of 2-iodo-2-phenylethanol (PIE) in an OrganicSolvent

A 250 ml round bottom flask was charged with 21 ml HI (55% aqueoussolution) and cooled to 0° C. Via an addition funnel, 20 grams ofstyrene oxide in 80 ml of diethylether were added over a one hourperiod. Diethylether (45 ml) was added and the water phase wasseparated. The leftover organic solution was dried with Na₂SO₄ andevaporated. Thirty-eight grams of a faint yellow solid were obtainedhaving a melting point of 71-72° C.

EXAMPLE 3 Synthesis of Diiodoxylene (DIX)

DIX was synthesized as reported in Finkelstein, Chem. Ber., 43, 1532(1910). A solution of 5.04 grams of sodium iodide in 24 ml of acetonewas added to a stirred solution of 3.69 grams of α,α′-dibromo-pxylene in90 ml of acetone in a 500 ml round bottom flask under argon. A solidprecipitated, and stirring was continued for 30 minutes. Water (250 ml)was added to the mixture to dissolve the salts. The mixture was thenvacuum filtered, washed with water several times, and vacuum dried atroom temperature overnight. The observed melting point was 175-178° C.

EXAMPLE 4 Synthesis of 2-iodo-2-phenylethanol from Mixed Calcium Salts

A mixture of CaI₂ and Ca(OH)₂ (6 grams and 1.6 grams, respectively) waskg placed in a 100 round bottom flask and 100 ml of water were added. HIwas generated by adding 2.4 ml of concentrated H₂SO₄ and the reactionmixture was cooled to 0° C. and 5 ml of ether were added. Via anaddition funnel, styrene ea oxide (5 grams) in 10 ml of diethyletherwere added dropwise over a 35-minute period, followed by 15 ml of ether.The organic layer was separated out and the water layer was washed with10 ml ether. The combined ether solutions were washed with 10 ml 10%NaHSO₃ and dried over Na₂SO₄. Evaporation yielded 7.9 grams of a lightyellow powder with a melting point from 64-67° C. NMR analysis wasconsistent with the reports in the literature.

EXAMPLE 5 Synthesis of n-Butyl Acrylate Prepolymer from2-iodo-2-phenylethanol

A 500 ml reactor as charged, with 150 ml of toluene, 150 grams n-butylacrylate, 7.4 grams of the 2-iodo-2-phenylethanol formed in Example 1,0.12 grams of AIBN and 5 ml of decane. The mixture was purged with argonfor one hour and then heated to 70° C. After 400 minutes the monomerconversion was measured to be 85% and the reaction mixture was cooled toroom temperature. The toluene was removed in vacuo and 150 ml of pentylacetate were added and subsequently removed in vacuo. The resultingpolymer was void of any residual monomer. NMR analysis showed both endgroups (CH₂OH and CHICOOR) and gave a number average molecular weight of5160 g/mol. Based on the ratio of 1-iodo-1-phenylethanol to monomer, atheoretical molecular weight of 4,500 g/mol was expected. Elementalanalysis yielded 3.3 wt. % iodine compared to 2.8 wt. % expected basedon conversion of monomer. MALDI-TOF analysis showed the presence of onlythe expected polymer species (FIG. 7).

EXAMPLE 6 Synthesis of n-Butyl Acrylate Prepolymer from2-iodo-2-phenylethanol

A 100 ml reactor was charged with 29 s toluene, 29 grams of n-butylacrylate, 1.5 grams of the 2-iodo-2-phenylethanol formed in Example 1and 0.246 gram of AIBN. The reaction was carried out as described inExample 5. Twenty-six grams of a viscous liquid were isolated. GPCanalysis (using polystyrene standards) showed M_(n) equal to 5130 g/moland PDI equal to 2.27 (theoretical M_(n) based on 1-iodo-1-phenylethanolto monomer was 4,500 g/mol). MALDI analysis showed the presence of onlythe expected polymer. No AIBN terminated species were observed.

EXAMPLE 7 Synthesis of n-Butyl Acrylate Prepolymer Using Ethyl2-iodopropionate

In a 50 ml reactor, 14.8 grams of n-butyl acrylate, 0.7 gram of ethyl2-iodopropionate, 0.013 gram AIBN and 15 ml of toluene were mixed. Byheating the mixture at 70° C. for 185 minutes, 88% of the monomerconverted to polymer. GPC analysis showed an M, equal to 8140 g/mol anda PDI equal to 2.57 (theoretical M_(n) was 3850 g/mol). MALDI analysisshowed only one polymer species consistent with an ethyl propionate endgroup.

EXAMPLE 8 Synthesis of n-Butyl Acrylate Prepolymer UsingIodoacetonitrile

A 50 ml reactor was charged with 15 grams of n-butyl acrylate, 0.34 gramof iodoacetonitrile, 15 ml of toluene, 0.025 gram of AIBN and 1 ml ofdecane. After heating the mixture at 65° C. for 4.45 hours, 95% of themonomer was converted. Evaporation of the reaction mixture yielded 10grams of a polymer having M_(n) equal to 12,100 g/mol and PDI equal to2.56. MALDI analysis showed only the presence of acetonitrile initiatedpolymers.

EXAMPLE 9 Synthesis of n-Butyl Acrylate Prepolymer Using DIX

A 500 ml 3-neck flask was charged with 8.6 grams of DIX formed inExample 3, 120 ml toluene, 112.7 grams of n-butyl acrylate, 0.32 gram ofAIBN and 8 ml of decane. The solution was purged with argon and thenheated at 75° C. for 450 minutes at which point 95% of the monomer wasconverted. The M_(n) was determined to be 2340 g/mol (theoretical M_(n)equal to 2080) and the PDI was determined to be 2.71. NMR analysisshowed that 17% of the benzylic iodide groups had not engaged in thereaction.

EXAMPLE 10 Synthesis of n-Butyl Acrylate Prepolymer Using DIX

A 500 ml, 4-necked round bottom flask was charged with 140 gramstoluene, 140.0 grams n-butyl acrylate and 20 ml decane used as internalGC standard followed by the addition of 1.53 grams of AIBN and 33.40grams DIX into the reactor. The solution was purged with argon for 30minutes. The reaction was run at 70° C. for 5 hours and gaschromatographic analysis indicated that 85% monomer was converted. Thesolution was cooled to 0° C. with ice water and transferred to a 500 mlround-bottomed flask. Toluene was removed using a rotavap at 45-50° C./5mm Hg followed by adding 150 ml pentyl acetate which was distilled at45-50° C./10 mm Hg in order to remove butyl acrylate residuals. The sameprocedure using pentyl acetate was repeated four times until no n-butylacrylate trace was detected by GC. The prepolymer was solvent-free andhad a light yellowish color, which indicated that a trace amount ofiodine was released from the prepolymer. Analysis by GPC (THF v.polystyrene standards) showed M_(n) equal to 1450 g/mol and PDI equal to1.58 (M_(n) theoretical equal to 1570 g/mol). NMR showed the presence ofthe DIX fragment and iodine end groups in the correct ratios. MALDI-TOFanalysis showed the presence of only the expected polymer species.

EXAMPLE 11 Synthesis of n-Butyl Acrylate Prepolymer Using Allyliodide

N-butyl acrylate (15 grams), cyclohexane (15 ml), decane (1 ml),allyliodide (0.14 gram) and AIBN (0.034 gram) were heated at 70° C. in a50 ml reactor for 12 hours. Monomer conversion by gas chromatography was97%. The leftover solvent and monomer were removed in vacuo. Molecularweight analysis showed an M_(n) equal to 22,800 g/mol (M_(n) theoreticalequal to 17,200 g/mol) and PDI equal to 2.69. NMR analysis showed thepresence of the allyl end group.

EXAMPLE 12 Synthesis of Styrene Prepolymer Using 2-iodo-2-phenylethanol

A 100 ml reactor was charged with 50 grams of styrene, 4.9 grams of2-iodo-2-phenylethanol formed in Example 1, 17 ml of cyclohexane, 1 gramAIBN and 2 ml of decane. The reaction was heated at 70° C. overnight.The polymer was precipitated from THF in methanol to yield 31.6 grams ofwhite powder. GPC analysis showed M_(n) equal to 1580 g/mol and PDIequal to 1.47 (M_(n) theoretical equal to 4400 g/mol). NMR and MALDIanalysis showed the presence of the 1-iodo-1-phenylethanol and iodineend groups.

EXAMPLE 13 Synthesis of Ethyl Acrylate Prepolymer Using2-iodo-2-phenylethanol

A mixture of 29.7 grams of ethyl acrylate, 1.49 grams of the formed inExample 1, 30 ml of toluene, 0.027 gram of AIBN and 2 ml of decane washeated at 70° C. for 5.5 hours. Gas chromatographic analysis showed 87%monomer conversion. The solvent and residual monomer were removed byevaporation to yield 24.6 grams of a very viscous liquid. GPC in THFversus polystyrene standards showed an M_(n) equal to 3500 g/mol and PDIequal to 2.97 (M_(n) theoretical equal to 4400 g/mol). NMR analysisshowed the presence of both end groups.

EXAMPLE 14 Synthesis of Ethylhexyl Acrylate prepolymer Using2-iodo-2-phenylethanol

In a 150 ml reaction flask were mixed 45 ml of ethylhexyl acrylate, 2.2g of 2-iodo-2-phenylethanol, 50 ml of toluene and 0.04 gram of AIBN. Themixture was heated at 70° C. for 280 minutes at which point 77% monomerwas converted. The toluene was removed under vacuo and the polymer wasprecipitated from a THF solution into methanol. The M_(n) by GPC versuspolystyrene standards was 5150 g/mol and PDI was equal to 2.35. NMRanalysis showed both end groups and gave a molecular weight of 4400g/mol (theoretical M_(n) expected to be 3700 g/mol).

EXAMPLE 15 Synthesis of n-Butyl Acrylate Prepolymer Using DIX

A 250 ml, 4-necked round bottom flask was fitted with a mechanicalagitator, argon inlet, condenser/gas bubbler and thermometer. Then, 40.0ml toluene, 40.0 grams (44.74 ml) n-butyl acrylate and 5.5 ml decaneused as internal GC standard were charged into the flask followed byadding 0.1642 gram AIBN and 3.5786 grams DIX into the reactor. Thesolution was purged with argon for 30 minutes. The flask was set in anoil bath at 70° C. The reaction was run at this temperature for 4 hoursand GC result indicated that 74% monomer was converted. Another 0.0420gram AIBN was added to get higher monomer conversion and thepolymerization was continued at 70° C. for another hour until an 84%conversion was reached. The solution was cooled to 0° C. with ice waterand transferred to a 250 ml round-bottomed flask. Toluene was removedusing a rotavap equipment set-up at 25° C./10 mm Hg. Then 50 ml pentylacetate was added and distilled at 50° C./10 mm HG in order to removedthe residual butyl acrylate. The same procedure using pentyl acetate wasrepeated three times until no n-butyl acrylate was detected by GC.

EXAMPLE 16 Synthesis of n-Butyl Acrylate Diol Polymer

To a reaction mixture containing all of the prepolymer formed in Example9 and 5% unreacted monomer were added 11.34 grams of mercaptoethanol and10 grams CaO. The reaction was heated to 73° C. for 55 minutes at whichpoint 55% of the mercaptoethanol had disappeared. The reaction mixturewas diluted with 100 ml of toluene and filtered. The filtrate was vacuumdried at 50° C. overnight. The resulting polymer was dissolved in 1.5 Lof ethanol and 1.5 L of water were added. The precipitate was recoveredand reprecipitated. NMR analysis showed that all iodine groups haddisappeared. The OH #(acetic anhydride method) was 17 (theoreticallyexpected 23). Elemental analysis showed 1.03 wt. % S and 0.5 wt. % ash.

EXAMPLE 17 Synthesis of n-Butyl Acrylate Diol Polymer

All of the prepolymer formed in Example 10 was transferred into a 250ml, 4-necked round bottom flask fitted with a mechanical agitator, argoninlet, condenser/gas bubbler and thermometer, followed by adding 30.0 mlDMF, 2.60 grams 3-mercapto-1-propanol and 3.90 grams potassiumcarbonate. The solution was stirred and purged with argon for 30minutes. The functionalization reaction was carried out at 40° C. for 10hours and a small amount of sample was taken out for NMR analysis. Thereaction was stopped by lowering the reactor to room temperature. Thesalt was removed by separating the solid phrase from the solution bycentrifuging at 6000 rpm for 15 minutes. The solution portion wastransferred into a 250 ml flask to remove DMF at 45° C./5 mm Hg. Then,50 ml cyclohexane was added into this flask and more salt wasprecipitated out from the solution and centrifuged out at 6000 rpm for10 minutes to separate the salt from the solution. Cyclohexane wasremoved by distillation at RT./20 mm Hg. OH# was 74.82. The conversionof the iodine end groups was complete by NMR analysis. MALDI analysis,as shown in FIG. 9, showed the presence of only one polymer speciesconsistent with the expected diol product. The final product was a clearand low viscosity fluid.

EXAMPLE 18 Synthesis of n-Butyl Acrylate Diol Polymer

The prepolymer formed in Example 5 (30 grams) and 1.08 grams of K₂CO₃were dissolved in 60 ml of DMF. The reaction was purged with argon for30 minutes to remove oxygen and 0.8 gram of mercaptoethanol wereinjected. The reaction was stirred at room temperature for 325 minutesand an additional 0.5 gram of K₂CO₃ arid 0.23 gram of mercaptoethanolwere added. After an additional 225 minutes, the reaction was filteredthrough a 1.2 micrometer filter. The DMF of the filtrate was removed invacuo and 60 ml of toluene were added. The resulting solution wasfiltered again through a 1.2 micrometer filter and the toluene wasremoved in vacuo. The last step was repeated using a 0.45 micrometerfilter. After removal of most the solvent, 31 grams of a very viscousoil was recovered. Analysis by NMR showed complete disappearance of theiodine end group of the starting material. Analysis using MALDI massspectroscopy showed that the majority (greater than 90%) of the samplehad the expected composition of the diol (see FIG. 8). The smallimpurity of this particular example showed the loss of butanol,presumably by chain end cyclization.

EXAMPLE 19 Synthesis of α-hydroxycarboxlic acid n-butyl acrylate)polymer

Fifteen grams of the 2-iodo-2-phenylethanol prepolymer formed in Example5 were dissolved in 30 ml of dry DMF. Then, 2.2 grams K₂CO₃ and 0.75gram of mercaptoacetic acid were added and the reaction was stirred atroom temperature for 4 hours. The mixture was filtered over a 1.2micrometer filter, the solvent was removed in vacuo and replaced with 60ml of toluene. After the mixture was filtered and evaporated once again,14 grams of a viscous liquid were obtained. NMR analysis show completeconversion of the iodine end groups and MALDI show incorporation of theacid into the polymer.

EXAMPLE 20 Synthesis of n-Butyl Acrylate Diol Polymer

All of the prepolymer of Example 15 was transferred into a 250 ml,4-necked round bottom flask, which was fitted with the mechanicalagitator, argon inlet, condenser/gas bubbler and thermometer, followedby adding 40.0 ml DMF, 2.211 grams 3-mercapto-1-propanol and 3.3170grams potassium carbonate. The substitution reaction was carried out at40° C. for 4 hours in small amounts and a small amount of sample wastaken for NMR analysis. The substitution continued to run at thistemperature for another 60 minutes and the reaction was then stopped bylowering the reactor to room temperature. The salt was removed byseparating the solid phase from the solution by centrifuging at 6000 rpmfor 15 minutes. The solution portion was transferred into a 250 ml flaskto remove DMF at 80° C.10 mm Hg. Then, 40 ml toluene were added to theflask and more salt was precipitated out from the solution andcentrifuged at 6000 rpm for 10 minutes to separate the salt from thesolution. Toluene was removed by distillation at 45° C./10 mm Hg. Thisprocedure was repeated three times.

EXAMPLE 21 Synthesis of n-Butyl Acrylate Diol Polymer

The bromine-terminated poly (n-butyl acrylate) prepolymer formed inExample 22 was displaced in a 100 ml round-bottom flask equipped withargon inlet Fifty milliliters DMF were added and the mixture was stirredto form a solution. The solution was purged with nitrogen, followed bypotassium carbonate (3.3 grams) and 3-mercapto-1-propanol were added.The mixture was stirred at 40° C. until all mercaptopropanol reacted, asevidenced by the GC analysis of the samples taken during the reaction.The mixture was then filtered and concentrated using a rotaryevaporator. Sixty ml toluene were added to the flask and the mixture wasfiltered again to remove any remaining salt. This procedure wasrepeated, with toluene and decane solvents, until all inorganic saltswere removed from the polymer. The solution was then concentrated andthe polymer was then dried in a vacuum oven at 60° C. The resultingpolyacrylate diol had a hydroxyl number of 53.46 and an M_(n) of 2114.

EXAMPLE 22 Synthesis of n-Butyl Acrylate Prepolymer Via ATRP Process

100 ml 3 neck flask was charged with CuBr (1.89 grams) in a glove bagunder positive argon pressure. The flask was capped with septa andremoved from the glove bag. A reflux condenser with a argon gas inletwas attached and the flask was placed under a positive argon pressure.The liquid components, n-butyl acrylate (15 ml), toluene (15 ml) anddecane (1 ml) were injected into the flask. α,α dibromo-p-xylene (1.73grams) was weighed out and poured into the flask. The solid residue waswasted into the solution with 5 ml of toluene. Bipyridine (6.18 grams)was weighed out and poured into the flask. The residual solid was washedinto the flask with the reaction liquor.

The solution was stirred rapidly (350 rpm) for five minutes to permitthe CuBr (BiPy)₂ complex to form. The solution became a dark brown.

The flask was lowered into an oil bath at 95° C. to start thepolymerization.

The reaction was run for five hours and then worked up by cooling anddiluting with toluene (15 ml) and filtering through alumina to removethe solid catalyst residue. A cloudy, light brown liquid was recovered.The liquid was treated with activated carbon, cell filtered through abed of celite. After evaporation of the solvent, 12.7 grams (84 wt. %)of a polymer were obtained.

EXAMPLE 23 Synthesis of Polyurethane Using Polyacrylate Diols

A mixture of 5.2 grams of the polyacrylate diol formed in Example 20, IDisophorone (5.2 grams), MDI (1.2 grams) and dibutyl tin dilaurate (200ppm) was heated in a large test-tube for 1 hour at 70° C. Butanediol(0.1 gram) was added and the resulting solution was poured into a teflonpan and heated in an oven at 80° C. for 4 hours. The resulting polymersolution was poured into 250 grams of cyclohexane. The insolublepolyurethane was separated and dried under vacuum overnight. The polymerproduct was analyzed by GPC (Mw equal to 56,400 and polydispersity equalto 2.5).

EXAMPLE 24 Hydrolysis Resistance Testing of Polyurethanes

The polyurethane of Example 23 was exposed to an aqueous media for 72hours at 95° C. The number average molecular weight of the sample,before and after exposure to the aqueous media, was determined by GPCand is recorded below in TABLE II. The percent molecular weight retainedafter each treatment corresponds to the hydrolysis resistance of thesample.

COMPARATIVE EXAMPLE 1

This example provides a comparison regarding end-functionalization withNippon Shokubai Japanese patent application Kokai No. 4-132706.

A 100 ml, three-necked round bottom flask was fitted with a stirringbar, argon inlet, condenser/gas bubbler and thermometer. Then 16.1 grams(18.0 ml) n-butyl acrylate and 0.7200 grams DIX were charged into theflask. DIX was employed, instead of the DIT taught and used in theNippon Shokubai patent application, because DIX is employed in thepresent invention and it was felt that the difference would not beconsidered material for the purposes of this comparison. The solutionwas purged with argon for 20 minutes. The flask was set in an oil bathat 60° C., polymerization was carried out at this temperature for 3hours and then the reactor temperature was lowered to room temperature.Then 40 ml TBIF was added and the mixture was stirred until ahomogeneous solution was obtained. Then, 1.3 ml 35% aqueous sodiumhydroxide were added and the hydrolysis reaction was carried out at 60°C. for six hours. The solution was concentrated to give a colorless andviscous sample. The sample was washed three times with 50 ml DM water toremove sodium hydroxide and then was dried in the vacuum oven at 90° C.for 12 hours.

The ¹H NMR analysis indicated the presence of a significant amount ofcarboxyl groups and carbon-carbon double bonds in the resultingpolyacrylate diol samples. Therefore, the hydrolysis of aniodo-functionalized polymer as taught by the Nippon Shokubai referenceis not an efficient method for preparation of high functionalitypolyacrylate diols.

The invention has been described with reference to preferred andalternate embodiments. Obviously, modifications and alterations willoccur to others upon the reading and understanding of thisspecification. The specification is intended to include all suchmodifications and alterations insofar as they come within the scope ofthe appended claims or the equivalents thereof.

What is claimed is:
 1. A process for forming a polymer having at leastone functionalized end group, the process comprising the steps of: (a)heating a mixture of an activated iodine reagent, a free-radicalinitiator, and at least one polymerizable monomer to form a pre-polymer,the activated iodine reagent being of the formula: R—I where R containsat least one radical stabilizing group and has 1-50 carbon atoms, theiodine and the radical stabilizing group are attached to the same carbonatom in R, and the radical stabilizing group is selected from the groupconsisting of an aryl, ester, amide, ketone, nitrile, halogen, andnitro; and (b) functionalizing the pre-polymer by reaction with anucleophilic reagent selected from mercaptoethanol, thioglycolic acid,mercaptopropanol, thiopropionic acid, allyl mercaptan, andmercaptoethylamine.
 2. The process of claim 1 wherein the activatediodine reagent is one selected from the group consisting ofiodoacetonitrile, ethyl 1-iodopropionate, 4-methylbenzyliodide and1-iodo-ethylbenzene.
 3. The process of claim 1 wherein the free-radicalinitiator is one selected from the group consisting of hydrogenperoxide, t-butyl hydroperoxide, t-butyl perbenzoate, t-amylperbenzoate, t-butyl peroctoate, t-amyl peroctoate, ditertiary butylperoxide, tertiary-amyl hydroperoxide, dibenzoyl peroxide, potassiumpersulfate and methyl ethyl ketone peroxide.
 4. The process of claim 1wherein the free-radical initiator is one selected from the groupconsisting of azobisisobutyronitrile, azobiscyanovaleric acid, azobis(hydroxethylcyanovaleramide), azobis (cyclohexanecarbonitrile), 2.2′azobis(4-methoxy-2,4-dimethylvaleronitrile),2.2′-azobis[2-methyl-N-(2-hydroxyethyl)propionamide].
 5. The process ofclaim 1 wherein the monomer is one selected from the group consisting ofstyrene and substituted derivatives thereof, conjugated dienes andsubstituted derivatives thereof, acrylates and substituted derivativesthereof, acrylonitrile, acrylic acid and mixtures thereof.
 6. Theprocess of claim 1 wherein the heating is conducted in a solvent or inbulk.
 7. The process of claim 6 wherein the solvent is one selected fromthe group consisting of toluene, amyl acetate, butyl acetate,pseudocumene, tetrahydrofuran, and dimethylformamide.
 8. The process ofclaim 7 wherein the solvent is toluene.
 9. The process of claim 1wherein the iodine reagent is preformed or formed in situ.
 10. Theprocess of claim 1 wherein the polymerizable monomer is added to themixture simultaneously, sequentially, batchwise or metered.
 11. Aprocess for forming a polymer having at least one functionalized endgroup, the process comprising the steps of: (a) heating a mixture of anactivated di-iodine reagent, a free-radical initiator, and at least onepolymerizable monomer to form a pre-polymer, the activated di-iodinereagent being of the formula: I—R—I where R contains at least oneradical stabilizing group and has 1-50 carbon atoms, the iodine and theradical stabilizing group are attached to the same carbon atom in R, andthe radical stabilizing group is selected from the group consisting ofan aryl, alkene, ester, acid, amide, ketone, nitrite, halogen,isocyanate, nitro and amine; and (b) functionalizing the pre-polymer byreaction with a nucleophilic reagent.
 12. The process of claim 11wherein the activated di-iodine reagent is α,α′-diiodoxylene or methyl2,5-diiodohexanedioate.
 13. The process of claim 11 wherein thefree-radical initiator is one selected from the group consisting ofperoxo compounds containing at least one O—O group.
 14. The process ofclaim 11 wherein the free-radical initiator is one selected from thegroup consisting of azobisisobutyronitrile, azobiscyanovaleric acid,azobis(hydroxethylcyanovaleramide), azobiscyanovaleric acid,azobis(hydroxethylcyanovaleramide), azobis(cyclohexanecarbonitrile),2.2′ azobis(4-methoxy-2,4-dimethylvaleronitrile),2.2′-azobis[2-methyl-N-(2-hydroxyethyl)propionamide].
 15. The process ofclaim 11 wherein the monomer is one selected from the group consistingof styrene and substituted derivatives thereof, conjugated dienes andsubstituted derivatives thereof, acrylates and substituted derivativesthereof, acrylonitrile, acrylic acid and mixtures thereof.
 16. Theprocess of claim 11 wherein the nucleophilic reagent is one selectedfrom the group consisting of mercaptoethanol, thioglycolic acid,mercaptopropanol, thiopropionic acid, allyl mercaptan, andmercaptoethylamine.
 17. The process of claim 11 wherein the heating isconducted in a solvent or in bulk.
 18. The process of claim 17 whereinthe solvent is one selected from the group consisting of toluene, amylacetate, butyl acetate, pseudocumene, tetrahydrofuran, anddimethylformamide.
 19. The process of claim 17 wherein the solvent istoluene.
 20. The process of claim 11 wherein the iodine reagent ispreformed or formed in situ.
 21. The process of claim 11 wherein thepolymerizable monomer is added to the mixture simultaneously,sequentially, batchwise or metered.
 22. A process for forming a polymerhaving at least one functionalized end group, the process comprising thesteps of: (a) heating a mixture of an iodine reagent having at least oneiodine end group, a free-radical initiator, and at least onepolymerizable monomer, the molar ratio of the free-radical initiator tothe iodine reagent being 10 to 0.001, the molar ratio of the monomer tothe iodine reagent being 10 to 1000; and (b) converting the iodine endgroup to the functionalized end group by reaction with a nucleophilicreagent wherein said iodine regent is selected from a compound of theformulae: Z₂—R—I or I—R—I where R contains at least one radicalstabilizing group and has 1-50 carbon atoms, the iodine and the radicalstabilizing group are attached to the same carbon atom in R, and theradical stabilizing group is selected from the group consisting of anaryl, alkene, ester, acid, amide, ketone, nitrile, halogen, isocyanate,nitro and amine, and Z₂ is selected from —OR₁, —N(R₁)₂, —SR₁, —COOR₁,—COOM, olefin of the type —CR₁═C(R₁)2, epoxide of the type

—SO₃M, —PO(OR₁)₂, —PO(R₁)₃, —P(R₁)₃, —N═C═O and —CR₁═O, wherein R₁ isequal to H or a group having 1-20 carbon atoms, R₁ being the same ordifferent for any Z₂ having more than one R₁, and wherein M is a metalion.
 23. The process of claim 22 wherein the monomer is selected fromthe group consisting of C₃-C₆ monoethylenically unsaturated carboxylicacids, and the alkaline metal and ammonium salts thereof. The C₃-C₆monoethylenically unsaturated carboxylic acids include acrylic acid,methacrylic acid, crotonic acid, vinyl acetic acid, maleic acid, fumaricacid and itaconic acid.
 24. The process of claim 22 wherein theactivated di-iodine reagent is α,α′-diiodoxylene or methyl2,5-diiodohexanedioate.
 25. The process of claim 22 wherein thefree-radical initiator is one selected from the group consisting ofhydrogen peroxide, t-butyl hydroperoxide, t-butyl perbenzoate, t-amylperbenzoate, t-butyl peroctoate, t-amyl peroctoate, ditertiary butylperoxide, tertiary-amyl hydroperoxide, dibenzoyl peroxide, potassium persulfate and methyl ethyl ketone peroxide.
 26. The process of claim 22wherein the free-radical initiator is one selected from the groupconsisting of azobisisobutyronitrile, azobiscyanovaleric acid,azobis(hydroxethylcyanovaleramide), azobis(cyclohexanecarbonitrile),2.2′ azobis(4-methoxy-2,4-dimethylvaleronitrile),2.2′-azobis[2-methyl-N-(2-hydroxyethyl)propionamide].
 27. The process ofclaim 22 wherein the monomer is one selected from the group consistingof styrene and substituted derivatives thereof, conjugated dienes andsubstituted derivatives thereof, acrylates and substituted derivativesthereof, and mixtures thereof.
 28. The process of claim 22 wherein thenucleophilic reagent is one selected from the group consisting ofmercaptoethanol, thioglycolic acid, mercaptopropanol, thiopropionicacid, allyl mercaptan, and mercaptoethylamine.
 29. The process of claim22 wherein the heating is conducted in a solvent or in bulk.
 30. Theprocess of claim 29 wherein the solvent is one selected from the groupconsisting of toluene, amyl acetate, butyl acetate, pseudocumene andtetrahydrofuran.
 31. The process of claim 29 wherein the solvent istoluene.
 32. The process of claim 22 wherein the iodine reagent ispreformed or formed in situ.
 33. The process of claim 22 wherein thepolymerizable monomer is added to the mixture simultaneously,sequentially, batchwise or metered.
 34. The process of claim 1, 11, or22 wherein said mixture in step (a) contains a base selected from ZnO,pyridine, 4-dimethylaminopyridine, diazabicyclo[5,4,0] undec-7-ene,K₂CO₃, K₃PO₄, NaHCO₃, basic alumina, triethylamine, and CaO, and1,4-diazabicyclo[2,2,2]octane.
 35. The process of claim 1, 11, or 22wherein said nucleophilic reagent is selected from a compoundrepresented by the formula: Z₁—R₂—YH where Y is selected from the groupconsisting of oxygen, sulfur, and NR₅, where R₅ is hydrogen or asubstituted or unsubstituted alkyl group or is not present when Z isdirectly bonded to the polymer, and where Z₁ is selected from the groupconsisting of —OR₁, —N(R₁)₂, —SR₁, —COOR₁, —COOM, olefin of the type—CR₁═C(R₁)₂, epoxide of the type

—SO₃M, —PO(OR₁)₂, —PO(R₁)₃, —P(R₁)₃, —N═C═O and —CR₁═O, wherein R₁ isequal to H or a group having 1-20 carbon atoms, R₁ being the same ordifferent for any Z₂ having more than one R₁, and wherein M is a metalion.